Obesity is a major medical problem affecting millions of individuals worldwide. In the United States alone, one in every two individuals is overweight, and one in every three individuals is obese. In addition to the psychosocial stigmas associated with such condition, overweight individuals often have a higher risk of acquiring significant debilitative illnesses such as insulin resistance, diabetes, hypertension, hyperlipidemia, degenerative arthritis, and atherosclerotic heart disease. Certain types of cancer, gallstones, varicose veins, thromboembolism, and hernias are also more prevalent among overweight individuals. Patients suffering from the condition often have a higher risk of surgical complications, which can lead to future life-threatening events such as myocardial infarction or ischemia. Weight loss often results in a significant reduction in these and other risks, and has been shown to significantly improve the mental health of obese individuals by improving their self-esteem and sense of well-being. The importance of proper weight management for obese individuals thus cannot be overemphasized.
The treatment of obesity typically includes lifestyle modifications such as regular exercise as well as certain dietary restrictions. The efficacy of such treatments is often low, however, since many obese patients are either unwilling or unable to comply with such behavioral changes. In some treatments where vigorous exercise is recommended to achieve an increase in energy output, the patient may be at greater risk of causing further damage to the body due to myocardial events associated with increased heart rates and physical exertion.
One treatment method for obesity involves the use of herbs, supplements, and/or pharmaceuticals to either increase metabolism or suppress appetite. While some stimulative and appetite suppressive drugs have had a limited success in the treatment of obesity, they rarely result in a satisfactory and sustained weight reduction. In some cases, the use of such drugs may be contraindicated, particularly for those individuals that may suffer from side-effects or who are at risk of becoming addicted. In addition, drug tolerance may also develop as a result of long-term use, reducing the effectiveness of such drugs to combat obesity for sustained periods of use. Other factors such as drug interactions and high cost may also limit the use of such drugs.
For morbidly obese patients (i.e. for those with a BMI over 40 or a BMI over 35 with co-morbidities), more invasive bariatric surgical procedures have been used to treat obesity. Some of these procedures may involve reducing the volume of the gastric cavity, for example, by creating a small pouch gastric bypass, or reducing the expansion capacity of the gastric cavity by placing a constrictive band around the stomach. Although bariatric surgery is frequently effective in combating obesity, such procedures are often more expensive and have higher complication and mortality rates.
As a less invasive technique to bariatric surgery, intragastric balloons were introduced in the early 1980's for treating obesity by partially filling the patient's stomach to produce a feeling of satiety or fullness. Such devices typically included a balloon that can be endoscopically inserted into the gastric cavity via the esophageal tube, and then inflated to partially fill to patient's stomach. Once inflated within the stomach, the distension caused by the balloon as well as by the presence of food stimulates various neuroreceptors located in the upper fundus of the stomach, causing the patient to experience an earlier feeling of fullness during meals. Continued use of the balloon typically results in a decrease in the daily caloric intake of the patient and subsequently a sustained weight loss.
Despite their effectiveness as a less invasive technique for treating obesity, many conventional intragastric balloons were initially limited to use in short-term programs of limited weight reduction, often prior to a more definitive bariatric surgery. A significant problem associated with these intragastric balloons was initially related to the manufacturing materials used, which were affected by the gastric acid within the stomach such that frequent replacement of the balloon was required. Other difficulties such as balloon rupture and/or migration also led to obstruction of the pylorus and the bowels in some patients, thus requiring additional surgery. In certain applications, the difficultly associated with placement of the balloon through the esophageal tube and the subsequent maintenance of the balloon once placed within the stomach also limit the effective use of such devices.
To overcome many of these drawbacks, more recent trends have focused on the use of percutaneous intragastric balloons for performing percutaneous gastronomy procedures on obese patients. In contrast to free-floating balloons, percutaneously inserted intragastric balloons are often secured in position via a support member such as a catheter or rod, typically at a location exterior of the patient's skin. While such devices overcome the problem of balloon migration and secondary bowel obstruction common in free-floating balloons, such devices are often difficult to place and maintain within the body. In addition, such devices often do not adequately address problems occurring at the placement site such as instability of the support catheter, gastric wall bleeding, and gastric content leak with the potential for peritonitis. Intolerance issues such as vomiting and abdominal pain as well as the embarrassment associated with the use of an extracorporeal device may further limit the use of such devices. Accordingly, there remains a need for effective solutions for the treatment of obesity.